There has been a lighting device that is provided in an interior part of a vehicle. The lighting device includes a light source (LED) and a light guide member that guides light from the light source to illuminate surroundings thereof. The light guide member includes an elongated core member made of acrylic resin and a cover member made of fluororesin. The elongated core member is covered with the cover member. The lighting device further includes a positioning member that positions an end portion of the light guide member with respect to the light source.
Usually, the cover member is fixed to the core member with pressure. Therefore, the cover member may be separated from the core member if an external force is applied to the cover member. If the cover member is separated from the core member, a space may be generated between the cover member and the core member and air may enter the space. This may cause unevenness in brightness of light from the light guide member.